I wish filter manufacturers would standardize the names and numbers of their products

I was trying to think of reasons, from patents to trademarks but it doesn't explain why they are not named after their wavelength. Each company has to have a numbering system which is consistent with the rest of their products.

It appears to be down to my original opinion that it was due to the results of the technicians who produce the filters for each manufacturer...their idea of a wratten 81B is this result. So to avoid confusion they give it a new name.